Some of them are more harmful than others. There are different types of SQL injection attacks, as mentioned before. Use a database user with restricted privileges So relying on client-side validation for SQL injection, for that matter, is a terrible idea. Everything a client sends you should be considered potentially harmful. In this case where you create the SQL query. You should validate on the server-side, ideally as close to the source as possible. Either by using tools like postman or old-school curl commands. Besides, it is pretty easy to do a basic HTTP call to the backend in a client-server architecture with a parameter that causes a SQL injection. You can remove client-side validation by altering some javascript code loaded in your browser. When looking at SQL injection, it is not a method you should rely on. Therefore you should be using client-side validation to help your user experience. To give the user direct feedback that a particular value is not valid is super helpful and user-friendly. However, this unfortunately only works for users that do not have bad intentions and want to use the system as designed. With client-side input validation, you can already prevent that invalid will be sent to your system logic. Do not rely on client-side input validation.Ĭlient-side input validation is great. Scan your code for SQL injection vulnerabilitiesġ. Use prepared statements and query parameterization

So let’s get started to make your application SQLi proof.ĭo not rely on client-side input validation In this cheatsheet, I will address eight best practices that every application programmer can use to prevent SQL injection attacks. Therefore the user’s input can alter the query’s original intent.Īdding a boolean to a where clause that is always true like ' OR 1=1Įscaping part of query by entering line comments -Įnding the initial query and start a new query ' DROP TABLE USERS Ĭonnecting data from multiple tables by using UNION The untrusted data that the user enters is concatenated with the query string. There are different types of SQL injection attacks, but in general, they all have a similar cause. If SQL injection is possible, smart attackers can create user input to steal valuable data, bypass authentication, or corrupt the records in your database. For instance, when filling in a web form. It occurs when a user adds untrusted data to a database query. SQL injection is one of the most dangerous vulnerabilities for online applications.

Mysql sqli cheat sheet